1. Field of the Invention
This invention pertains to flow control devices, in particular, open ditch or canal flow devices and more specifically devices to maintain levels in flowing streams and canals.
2. Description of the Prior Art
The inventor has commissioned a patent novelty search on the invention and the following prior art was uncovered:
______________________________________ Patent Number Origin Date Classification ______________________________________ 1,062,364 U.S.A. May 20, 1913 405/94 ______________________________________
This invention is directed to opening and closing a swinging gate to allow irrigation water to flow out of an irrigation waterway into a side ditch by use of a set of blades that rotate in the water flow. It is not a flow control device.
______________________________________ Patent Number Origin Date Classification ______________________________________ 351,521 Germany April 8, 1922 405/100 ______________________________________
This invention is directed to controlling water flow between parallel ditches and utilizes a gate extending from an arm that is bifulcrumed from a distantly mounted ballast.
______________________________________ Origin Date Classification ______________________________________ France October 16, 1952 405/100 ______________________________________
FIG. 9 shows an upstream level maintaining device that comprises a leaf and float element spaced apart from a counterweight mounted on an intermediate pivotal axis. While this is the only upstream level control found in the search, its function is totally different from the instant invention, depending upon a combination of leaf weight and floatation to overcome the counterweight; a complex relationship.
______________________________________ Patent Number Origin Date Classification ______________________________________ 683,630 U.S.A. Sept. 26, 1972 61/23 405/100 ______________________________________
This invention is concerned with devices to link the gate or apron to the cross-frame for precise adjustment and centering of the apron.
While development of downstream level controllers is evidenced the prior art, there is little or no upstream level control development. The need for upstream level control is important. For instance, in the treatment of sewage, any spillage over wiers and dams will cause turbulence and allow release of noxious fumes, such as sulfides. In the treatment of water, such spillage can result in release of costly chlorine that is used to kill bacteria and control algae growth. In other areas, such as in irrigation and water supply canals, control of upstream levels not only reduces water loss but also controls erosion due to turbulence caused by unrestrained water level changes.
The present invention controls upstream levels through a wide range, not limited to the height of the pivoted axis. In addition, the controlled level may be adjusted upward or downward by simply moving the ballast along the arm and the distance of ballast movement may be converted directly into stream level height. Thus, the tedious job of balancing the ballast to achieve a desired controlled level is eliminated. Further, much of the prior art limits the controlled level to the centerline of the pivotal axis. This would seem to pose serious problems of moisture damage to the axis saddles or at least require expensive preventative measures be taken to insure bearing dryness. Finally, this invention controls water level and at the same time, quells any turbulence caused by rapid level changes. Thus, when used in series they can effectively reduce soil erosion and other maladies caused by the flow of turbulent water, as well as provide effective control for large water usage operations such as turbines.